A ligament is a piece of fibrous tissue which connects one bone to another within the body. Ligaments are frequently damaged (e.g., detached, torn or ruptured) as the result of injury or accident. A damaged ligament can impede proper stability and motion of a joint and cause significant pain. A damaged ligament can be replaced or repaired using various procedures, a choice of which can depend on the particular ligament to be restored and on the extent of the damage. When ligaments are damaged, surgical reconstruction can be necessary, as the ligaments may not regenerate on their own.
An example of a ligament that is frequently damaged as a result of injury, overexertion, aging and/or accident is the anterior cruciate ligament (ACL) that extends between a top of the tibia and a bottom of the femur. Other ligaments that are often damaged and may need to be replaced include a posterior cruciate ligament (PCL) and medial collateral ligament (MCL). A damaged ACL, PCL, or MCL can cause instability of the knee joint, arthritis, and substantial pain.
ACL reconstruction or repair typically includes the use of a tendon graft replacement procedure which usually involves, for example, drilling a bone tunnel through the tibia and the femur. Then a graft, which may be an artificial ligament or harvested graft, such as a tendon, is secured at the sites where the natural ligament attaches.
Harvesting a tendon graft can be a challenging task that can define the outcome of the ACL reconstruction procedure. A number of conventional procedures exist for harvesting a tendon graft from a donor site. However, many existing approaches have certain shortcomings. For example, a traditional incision for graft harvesting is made anteriorly, at a location in the subject's knee where the semitendinosus and gracilis tendons are not separate tendons, which can complicate identification of the tendons. Furthermore, accessory bands arising from the semitendinosus and gracilis tendons can complicate tendon harvesting by diverting a harvesting instrument such that the main tendon can be cut short at the accessory band level. Such premature amputation of the tendon can result in a graft that is too short to allow adequate ACL reconstruction.
Accordingly, there is a need for improved graft harvesting instruments and techniques for using such instruments.